Returns user at run time, will log into seperate file and leave human readable date/time with real username and logged in username. Add line ' perl runuser.pl' to your bashrc file to have it run upon TTY/Shell interaction.

runuser.pl

#! /usr/tmp/env perl

use strict;
use 5.010;

my $user = $ENV{USER};
my $logname = $ENV{LOGNAME};
my $file_directory = "./ranby.txt";
# my $second_log = "./second.txt";
my $filename = "ranby.txt";
# my $second = "second.txt";
my $timestamp = localtime(time);
# my $path = shift || '/';
 
# traverse($path);
 
# sub traverse {
   # my @queue = @_;
 
    #while (@queue) {
       # my $thing = shift @queue;
        #say $thing;
        #next if not -d $thing;
        #opendir my $dh, $thing or die;
        #while (my $sub = readdir $dh) {
            #next if $sub eq '.' or $sub eq '..';
            #push @queue, "$thing/$sub";
       # }
        #closedir $dh;
    #}
    #return;
#}

open(my $filename, ">>", $file_directory)   || die "cant open $file_directory: $!";
binmode($filename);
print $filename "$timestamp, by $user, on $logname\n";
close($filename)	|| die "cant close $file_directory: $! ";